#include "gd.h"

#include "gd_intern.h"

/* Filters function added on 2003/12
 * by Pierre-Alain Joye (pierre@php.net)
 **/
/* Begin filters function */

/* invert src image */
int gdImageNegate(gdImagePtr src)
{
  int x, y;
  int r,g,b,a;
  int new_pxl, pxl;

  if (src==NULL) {
    return 0;
  }

  for (y=0; y<src->sy; ++y) {
    for (x=0; x<src->sx; ++x) {
      pxl = gdImageGetPixel(src, x, y);
      r = gdImageRed(src, pxl);
      g = gdImageGreen(src, pxl);
      b = gdImageBlue(src, pxl);
      a = gdImageAlpha(src, pxl);

      new_pxl = gdImageColorAllocateAlpha(src, 255-r, 255-g, 255-b, a);
      if (new_pxl == -1) {
        new_pxl = gdImageColorClosestAlpha(src, 255-r, 255-g, 255-b, a);
      }
      gdImageSetPixel (src, x, y, new_pxl);
    }
  }
  return 1;
}

/* Convert the image src to a grayscale image */
int gdImageGrayScale(gdImagePtr src)
{
  int x, y;
  int r,g,b,a;
  int new_pxl, pxl;

  if (src==NULL) {
    return 0;
  }

  for (y=0; y<src->sy; ++y) {
    for (x=0; x<src->sx; ++x) {
      pxl = gdImageGetPixel(src, x, y);
      r = gdImageRed(src, pxl);
      g = gdImageGreen(src, pxl);
      b = gdImageBlue(src, pxl);
      a = gdImageAlpha(src, pxl);
      r = g = b = (int) (.299 * r + .587 * g + .114 * b);

      new_pxl = gdImageColorAllocateAlpha(src, r, g, b, a);
      if (new_pxl == -1) {
        new_pxl = gdImageColorClosestAlpha(src, r, g, b, a);
      }
      gdImageSetPixel (src, x, y, new_pxl);
    }
  }
  return 1;
}

/* Set the brightness level <level> for the image src */
int gdImageBrightness(gdImagePtr src, int brightness)
{
  int x, y;
  int r,g,b,a;
  int new_pxl, pxl;

  if (src==NULL || (brightness < -255 || brightness>255)) {
    return 0;
  }

  if (brightness==0) {
    return 1;
  }

  for (y=0; y<src->sy; ++y) {
    for (x=0; x<src->sx; ++x) {
      pxl = gdImageGetPixel(src, x, y);

      r = gdImageRed(src, pxl);
      g = gdImageGreen(src, pxl);
      b = gdImageBlue(src, pxl);
      a = gdImageAlpha(src, pxl);

      r = r + brightness;
      g = g + brightness;
      b = b + brightness;

      r = (r > 255)? 255 : ((r < 0)? 0:r);
      g = (g > 255)? 255 : ((g < 0)? 0:g);
      b = (b > 255)? 255 : ((b < 0)? 0:b);

      new_pxl = gdImageColorAllocateAlpha(src, (int)r, (int)g, (int)b, a);
      if (new_pxl == -1) {
        new_pxl = gdImageColorClosestAlpha(src, (int)r, (int)g, (int)b, a);
      }
      gdImageSetPixel (src, x, y, new_pxl);
    }
  }
  return 1;
}


int gdImageContrast(gdImagePtr src, double contrast)
{
  int x, y;
  int r,g,b,a;
  double rf,gf,bf;
  int new_pxl, pxl;

  if (src==NULL) {
    return 0;
  }

  contrast = (double)(100.0-contrast)/100.0;
  contrast = contrast*contrast;

  for (y=0; y<src->sy; ++y) {
    for (x=0; x<src->sx; ++x) {
      pxl = gdImageGetPixel(src, x, y);

      r = gdImageRed(src, pxl);
      g = gdImageGreen(src, pxl);
      b = gdImageBlue(src, pxl);
      a = gdImageAlpha(src, pxl);

      rf = (double)r/255.0;
      rf = rf-0.5;
      rf = rf*contrast;
      rf = rf+0.5;
      rf = rf*255.0;

      bf = (double)b/255.0;
      bf = bf-0.5;
      bf = bf*contrast;
      bf = bf+0.5;
      bf = bf*255.0;

      gf = (double)g/255.0;
      gf = gf-0.5;
      gf = gf*contrast;
      gf = gf+0.5;
      gf = gf*255.0;

      rf = (rf > 255.0)? 255.0 : ((rf < 0.0)? 0.0:rf);
      gf = (gf > 255.0)? 255.0 : ((gf < 0.0)? 0.0:gf);
      bf = (bf > 255.0)? 255.0 : ((bf < 0.0)? 0.0:bf);

      new_pxl = gdImageColorAllocateAlpha(src, (int)rf, (int)gf, (int)bf, a);
      if (new_pxl == -1) {
        new_pxl = gdImageColorClosestAlpha(src, (int)rf, (int)gf, (int)bf, a);
      }
      gdImageSetPixel (src, x, y, new_pxl);
    }
  }
  return 1;
}


int gdImageColor(gdImagePtr src, const int red, const int green, const int blue, const int alpha)
{
  int x, y;
  int new_pxl, pxl;

  if (src == NULL) {
    return 0;
  }

  for (y=0; y<src->sy; ++y) {
    for (x=0; x<src->sx; ++x) {
      int r,g,b,a;

      pxl = gdImageGetPixel(src, x, y);
      r = gdImageRed(src, pxl);
      g = gdImageGreen(src, pxl);
      b = gdImageBlue(src, pxl);
      a = gdImageAlpha(src, pxl);

      r = r + red;
      g = g + green;
      b = b + blue;
      a = a + alpha;

      r = (r > 255)? 255 : ((r < 0)? 0 : r);
      g = (g > 255)? 255 : ((g < 0)? 0 : g);
      b = (b > 255)? 255 : ((b < 0)? 0 : b);
      a = (a > 127)? 127 : ((a < 0)? 0 : a);

      new_pxl = gdImageColorAllocateAlpha(src, r, g, b, a);
      if (new_pxl == -1) {
        new_pxl = gdImageColorClosestAlpha(src, r, g, b, a);
      }
      gdImageSetPixel (src, x, y, new_pxl);
    }
  }
  return 1;
}

int gdImageConvolution(gdImagePtr src, float filter[3][3], float filter_div, float offset)
{
  int         x, y, i, j, new_a;
  float       new_r, new_g, new_b;
  int         new_pxl, pxl=0;
  gdImagePtr  srcback;

  if (src==NULL) {
    return 0;
  }

  /* We need the orinal image with each safe neoghb. pixel */
  srcback = gdImageCreateTrueColor (src->sx, src->sy);
  if (srcback==NULL) {
    return 0;
  }

  gdImageSaveAlpha(srcback, 1);
  new_pxl = gdImageColorAllocateAlpha(srcback, 0, 0, 0, 127);
  gdImageFill(srcback, 0, 0, new_pxl);

  gdImageCopy(srcback, src,0,0,0,0,src->sx,src->sy);

  for ( y=0; y<src->sy; y++) {
    for(x=0; x<src->sx; x++) {
      new_r = new_g = new_b = 0;
      new_a = gdImageAlpha(srcback, pxl);

      for (j=0; j<3; j++) {
        int yv = MIN(MAX(y - 1 + j, 0), src->sy - 1);
        for (i=0; i<3; i++) {
                pxl = gdImageGetPixel(srcback, MIN(MAX(x - 1 + i, 0), src->sx - 1), yv);
          new_r += (float)gdImageRed(srcback, pxl) * filter[j][i];
          new_g += (float)gdImageGreen(srcback, pxl) * filter[j][i];
          new_b += (float)gdImageBlue(srcback, pxl) * filter[j][i];
        }
      }

      new_r = (new_r/filter_div)+offset;
      new_g = (new_g/filter_div)+offset;
      new_b = (new_b/filter_div)+offset;

      new_r = (new_r > 255.0f)? 255.0f : ((new_r < 0.0f)? 0.0f:new_r);
      new_g = (new_g > 255.0f)? 255.0f : ((new_g < 0.0f)? 0.0f:new_g);
      new_b = (new_b > 255.0f)? 255.0f : ((new_b < 0.0f)? 0.0f:new_b);

      new_pxl = gdImageColorAllocateAlpha(src, (int)new_r, (int)new_g, (int)new_b, new_a);
      if (new_pxl == -1) {
        new_pxl = gdImageColorClosestAlpha(src, (int)new_r, (int)new_g, (int)new_b, new_a);
      }
      gdImageSetPixel (src, x, y, new_pxl);
    }
  }
  gdImageDestroy(srcback);
  return 1;
}

int gdImageSelectiveBlur( gdImagePtr src)
{
  int         x, y, i, j;
  float       new_r, new_g, new_b;
  int         new_pxl, cpxl, pxl, new_a=0;
  float flt_r [3][3];
  float flt_g [3][3];
  float flt_b [3][3];
  float flt_r_sum, flt_g_sum, flt_b_sum;

  gdImagePtr srcback;

  if (src==NULL) {
    return 0;
  }

  /* We need the orinal image with each safe neoghb. pixel */
  srcback = gdImageCreateTrueColor (src->sx, src->sy);
  if (srcback==NULL) {
    return 0;
  }
  gdImageCopy(srcback, src,0,0,0,0,src->sx,src->sy);

  for(y = 0; y<src->sy; y++) {
    for (x=0; x<src->sx; x++) {
          flt_r_sum = flt_g_sum = flt_b_sum = 0.0;
      cpxl = gdImageGetPixel(srcback, x, y);

      for (j=0; j<3; j++) {
        for (i=0; i<3; i++) {
          if ((j == 1) && (i == 1)) {
            flt_r[1][1] = flt_g[1][1] = flt_b[1][1] = 0.5;
          } else {
            pxl = gdImageGetPixel(srcback, x-(3>>1)+i, y-(3>>1)+j);
            new_a = gdImageAlpha(srcback, pxl);

            new_r = ((float)gdImageRed(srcback, cpxl)) - ((float)gdImageRed (srcback, pxl));

            if (new_r < 0.0f) {
              new_r = -new_r;
            }
            if (new_r != 0) {
              flt_r[j][i] = 1.0f/new_r;
            } else {
              flt_r[j][i] = 1.0f;
            }

            new_g = ((float)gdImageGreen(srcback, cpxl)) - ((float)gdImageGreen(srcback, pxl));

            if (new_g < 0.0f) {
              new_g = -new_g;
            }
            if (new_g != 0) {
              flt_g[j][i] = 1.0f/new_g;
            } else {
              flt_g[j][i] = 1.0f;
            }

            new_b = ((float)gdImageBlue(srcback, cpxl)) - ((float)gdImageBlue(srcback, pxl));

            if (new_b < 0.0f) {
              new_b = -new_b;
            }
            if (new_b != 0) {
              flt_b[j][i] = 1.0f/new_b;
            } else {
              flt_b[j][i] = 1.0f;
            }
          }

          flt_r_sum += flt_r[j][i];
          flt_g_sum += flt_g[j][i];
          flt_b_sum += flt_b [j][i];
        }
      }

      for (j=0; j<3; j++) {
        for (i=0; i<3; i++) {
          if (flt_r_sum != 0.0) {
            flt_r[j][i] /= flt_r_sum;
          }
          if (flt_g_sum != 0.0) {
            flt_g[j][i] /= flt_g_sum;
          }
          if (flt_b_sum != 0.0) {
            flt_b [j][i] /= flt_b_sum;
          }
        }
      }

      new_r = new_g = new_b = 0.0;

      for (j=0; j<3; j++) {
        for (i=0; i<3; i++) {
          pxl = gdImageGetPixel(src, x-(3>>1)+i, y-(3>>1)+j);
          new_r += (float)gdImageRed(srcback, pxl) * flt_r[j][i];
          new_g += (float)gdImageGreen(srcback, pxl) * flt_g[j][i];
          new_b += (float)gdImageBlue(srcback, pxl) * flt_b[j][i];
        }
      }

      new_r = (new_r > 255.0f)? 255.0f : ((new_r < 0.0f)? 0.0f:new_r);
      new_g = (new_g > 255.0f)? 255.0f : ((new_g < 0.0f)? 0.0f:new_g);
      new_b = (new_b > 255.0f)? 255.0f : ((new_b < 0.0f)? 0.0f:new_b);
      new_pxl = gdImageColorAllocateAlpha(src, (int)new_r, (int)new_g, (int)new_b, new_a);
      if (new_pxl == -1) {
        new_pxl = gdImageColorClosestAlpha(src, (int)new_r, (int)new_g, (int)new_b, new_a);
      }
      gdImageSetPixel (src, x, y, new_pxl);
    }
  }
  gdImageDestroy(srcback);
  return 1;
}

int gdImageEdgeDetectQuick(gdImagePtr src)
{
  float filter[3][3] =  {{-1.0,0.0,-1.0},
        {0.0,4.0,0.0},
        {-1.0,0.0,-1.0}};

  return gdImageConvolution(src, filter, 1, 127);
}

int gdImageGaussianBlur(gdImagePtr im)
{
  float filter[3][3] =  {{1.0,2.0,1.0},
        {2.0,4.0,2.0},
        {1.0,2.0,1.0}};

  return gdImageConvolution(im, filter, 16, 0);
}

int gdImageEmboss(gdImagePtr im)
{
/*
  float filter[3][3] =  {{1.0,1.0,1.0},
        {0.0,0.0,0.0},
        {-1.0,-1.0,-1.0}};
*/
  float filter[3][3] =  {{ 1.5, 0.0, 0.0},
         { 0.0, 0.0, 0.0},
         { 0.0, 0.0,-1.5}};

  return gdImageConvolution(im, filter, 1, 127);
}

int gdImageMeanRemoval(gdImagePtr im)
{
  float filter[3][3] =  {{-1.0,-1.0,-1.0},
        {-1.0,9.0,-1.0},
        {-1.0,-1.0,-1.0}};

  return gdImageConvolution(im, filter, 1, 0);
}

int gdImageSmooth(gdImagePtr im, float weight)
{
  float filter[3][3] =  {{1.0,1.0,1.0},
        {1.0,0.0,1.0},
        {1.0,1.0,1.0}};

  filter[1][1] = weight;

  return gdImageConvolution(im, filter, weight+8, 0);
}
/* End filters function */
